Improvement in slate-frames



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Letters .Patent No. 101,798, dated April 12, 1870.

-*bop* IMPROVEMENT IN SLATETFRAMESV.

The Schedule referred to in these Letters Patent and makugpart of the same.

I, WILLIAM A. WILBE, of Malden, in the county of Middlesex and State of Massachusetts, have invented an Improvement in School Slate-Frames, of which the following is a description and specification.

A Nature (mtl Object of thel Invention.

It is made by vnlcanizing India-rubber compound, or other elastic compound, upon the corners of the common slate-frame, so as to entirely cover the wood part of 'the slate-frame at the corners, on the outer edge and sides, and so shaped on the sides of the frame that the edges of the compound, form a line with the inner edges of the frame, as represented in the drawing hereto annexed, so that in whatever position the slate-frame may be, when the corners are thus covered with the compound as aforesaid, whether setting up edgewise or lying flatwise upon the bench, desk, or table, the bearing will be wholly uponsaid compound.

The object of the' invention is to'prevent noise in the use ofthe slate or when it falls, and to prevent it from 'breaking when it falls, and to prevent the slate. frame from marring or scratching whatever it rests upon.

To prepare the counnon slate-frame for vulcanizing the rubber, or other elastic compound, upon the corners as aforesaid, the corners of the frame are rounded a little, if they are not already, and three holes of, sa-y, one-sixteenth to one-eighth of an inch in diameter, are bored through the frame near the corners, as seen in the drawing, one near the corner of the slate, near the inner edge of the frame, and the others near the outer edges of the frame, and which are lled, also, with the compound, in the process of vulcanizing it upon the corners, as aforesaid, and which the more securely fastens the compound upon the corners ofv the frame, and fastens the slate-frame together the stronger.

Description. of the Accompanying Drawing.

The drawing contains but one figure, and represents one side of the common slate-flame and slate, with my improvements complete on three of the corners, and

one corner, D, with the compound shaved off on the side exposed to view, as seen in the drawing, in order that it may be-the better seen in what manner the corners are covered with said compound and the holes through the corners filled.

General Description.

A is the slate, and

B, the frame of it in common use.

C is the compound, vulcanized onto the corners, as aforesaid, and shaped as seen inthe drawing, the compound extending outside the corners and edge of. the slate-frame some one-sixteenth of an inch or so, and is about that thickness on each side of the frame.

D are the holes before spoken of, made through the corners of the frame, and which are filled with the compound when the corners are covered with it, as aforesaid, and hence, in the process of vulcanizing the compound onto the corners of the frame, the compound in the holes is united to the compound on thc sides of the frame'.

I claim as my inventionrlhe vulcanizing of the India-rubber compound, or other elastic compound, onto the corners of the common slate-frame, to wit: the parts C and D, as shown in the drawing.

- XVILLIAM A'. VILDE.

Witnesses:

E. B. SMrrH, 'L. W. Howes. 

